Consumers often receive recommendations on products and/or services from various sources, such as merchants, experts, advertisers, friends, families, etc. Such recommendations may be provided to the consumers at any time, but usually when the consumers express interest in certain types of products or services. Sometimes, the recommended products or services are determined based on what specific products or services the other consumers, who are also interested in similar types of products or services, have purchased in the past. For example, when a consumer purchases a book from amazon.com, an Internet-based merchant that sells various types of products, amazon.com may recommend to the consumer other books that have been purchased by other consumers who have also purchased, in the past, the same book that is currently being purchased by the consumer. As another example, when a consumer wants to purchase a digital camera, he may ask his friends what brands and models of digital cameras they have purchased and make a selection based on his friends' recommendations.